diff --git a/alib2algo/src/stringology/query/BitParallelismFactors.h b/alib2algo/src/stringology/query/BitParallelismFactors.h
index f2e2b84a0eeb620af70ee078bd869c8a916823e4..a58aeded56c77a60c3267d184f422ae6f3a11af2 100644
--- a/alib2algo/src/stringology/query/BitParallelismFactors.h
+++ b/alib2algo/src/stringology/query/BitParallelismFactors.h
@@ -50,14 +50,14 @@ ext::set < unsigned > BitParallelismFactors::query ( const indexes::stringology:
 	if ( symbolVectorIter == bitParallelIndex.getData ( ).end ( ) )
 		return { };
 
-	ext::vector < bool > indexVector = symbolVectorIter->second;
+	ext::vector < bool > indexVector = symbolVectorIter->second << 1;
 
 	for ( ++ symbolIter; symbolIter != string.getContent ( ).end ( ); ++ symbolIter ) {
 		symbolVectorIter = bitParallelIndex.getData ( ).find ( * symbolIter );
 		if ( symbolVectorIter == bitParallelIndex.getData ( ).end ( ) )
 			return { };
 
-		indexVector = ( indexVector << 1 ) & symbolVectorIter->second;
+		indexVector = ( indexVector & symbolVectorIter->second ) << 1;
 	}
 
 	ext::set < unsigned > res;
diff --git a/alib2algo/src/stringology/query/CompressedBitParallelismFactors.h b/alib2algo/src/stringology/query/CompressedBitParallelismFactors.h
index 474ebe3a4ad4beed6727b589d1ea11af43409217..e11f45ff9200ff184819c6cffd194abb27a73380 100644
--- a/alib2algo/src/stringology/query/CompressedBitParallelismFactors.h
+++ b/alib2algo/src/stringology/query/CompressedBitParallelismFactors.h
@@ -51,20 +51,20 @@ ext::set < unsigned > CompressedBitParallelismFactors::query ( const indexes::st
 	if ( symbolVectorIter == compressedBitParallelIndex.getData ( ).end ( ) )
 		return { };
 
-	common::SparseBoolVector indexVector = symbolVectorIter->second;
+	common::SparseBoolVector indexVector = symbolVectorIter->second << 1;
 
 	for ( ++ symbolIter; symbolIter != string.getContent ( ).end ( ); ++ symbolIter ) {
 		symbolVectorIter = compressedBitParallelIndex.getData ( ).find ( * symbolIter );
 		if ( symbolVectorIter == compressedBitParallelIndex.getData ( ).end ( ) )
 			return { };
 
-		indexVector = ( indexVector << 1 ) & symbolVectorIter->second;
+		indexVector = ( indexVector & symbolVectorIter->second ) << 1;
 	}
 
 	ext::set < unsigned > res;
 
 	for ( unsigned i : indexVector )
-		res.insert ( i - string.getContent ( ).size ( ) + 1 );
+		res.insert ( i - string.getContent ( ).size ( ) );
 
 	return res;
 }